Which quantum number defines the orientation of orbital in the space around the nucleus?

Options

A. Principal quantum number `(n)`
B. Angular momentum quantum number(l)
C. Magnetic quantum number `(m_(l))`
D. Spin quantum number `(m_(s))`

Answer

To solve the question "Which quantum number defines the orientation of orbital in the space around the nucleus?", we can follow these steps:

### Step 1: Understand the Types of Quantum Numbers
Quantum numbers are used to describe the properties of atomic orbitals and the electrons in those orbitals. There are four types of quantum numbers:
1. Principal quantum number (n)
2. Angular momentum quantum number (l)
3. Magnetic quantum number (m)
4. Spin quantum number (ms)

### Step 2: Analyze Each Quantum Number
- **Principal Quantum Number (n)**: This quantum number indicates the size and energy level of the orbital. It does not provide information about the orientation of the orbital.

- **Angular Momentum Quantum Number (l)**: This quantum number defines the shape of the orbital (s, p, d, f) but does not specify its orientation in space.

- **Magnetic Quantum Number (m)**: This quantum number directly relates to the orientation of the orbital in space. It can take on integer values ranging from -l to +l, which indicates how the orbital is oriented in a magnetic field.

- **Spin Quantum Number (ms)**: This quantum number describes the intrinsic spin of the electron within the orbital, not the orientation of the orbital itself.

### Step 3: Identify the Correct Answer
From the analysis, we can conclude that the **magnetic quantum number (m)** is the quantum number that defines the orientation of the orbital in space around the nucleus.

### Final Answer
The correct answer is **C: Magnetic Quantum Number (m)**.

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